This invention is related to the field of telephony,and in particular to the call waiting feature.
Call waiting is a feature provided by a telephone service provider. The feature allows a user to be notified of incoming telephone calls while the user is already engaged in a previous telephone call. Typically, a central office of the telephone service provider issues a Subscriber Alert Signal (SAS) tone to inform the user that a new incoming call is available. Further, if the user subscribes to Caller ID Type 2 service, also known as Caller ID with Call Waiting (CID/CW), the central office issues a Caller ID Alert Signal (CAS) tone, as described in Bellcore standard FR12 (incorporated herein by reference), and further issues Caller ID data, in frequency shift keying (FSK) form, to provide the user with data identifying the incoming caller.
The incoming caller hears a periodic ringing sound from a speaker of the incoming caller""s telephone while the SAS tone, CAS tone, and Type 2 Caller ID data are being transmitted to the user. If the user elects to speak to the incoming caller and to temporarily place the previously existing call into a hold status, the user manipulates a switch-hook of the user""s telephone, and the central office responds by connecting the user to the incoming caller while placing the previous caller into the hold status. The user can toggle back and forth between the two parties (the first party to the previous call and the second party, hereinbefore identified as the incoming caller) indefinitely by continuing to activate the switch-hook of the user""s telephone.
An advantage of the call waiting feature is that the user is made aware of an incoming call even though the user is engaged in a previous telephone call. A further advantage is that, depending on the capabilities of the user""s telephone and the service provided by the telephone service provider, the user may be provided with information related to the incoming call, such as Caller ID data. Some users, however, may elect to maintain the initial connection and not switch to the incoming call. For example, these users may perceive that it is rude to cut off a present call, and will prefer, based on the Caller ID data, to call the incoming caller back after the present call is complete.
According to conventional practice, however, the incoming caller is not aware that the user is engaged in a previous telephone call, and may erroneously interpret the lack of an answer to the incoming call as an indication that the user is not at home. This can be problematic. For example, the incoming caller may not stay near the incoming caller""s telephone after trying unsuccessfully to contact the user, and may therefore miss the return call from the user. Further, the user""s safety may be jeopardized if the lack of an answer to the incoming call erroneously informs others that the user""s home is unoccupied. A need exists, therefore for a process, preferably based on user preferences, that informs an incoming caller that the user is presently engaged in a telephone call.
In a first embodiment according to the invention, a method is provided for handling an incoming call from an incoming telephone directed to a target telephone that is engaged in a present call. The method includes the steps of issuing a first signal to the target telephone to inform the target telephone of the incoming call, and issuing a second signal to the incoming telephone to inform the incoming telephone that the target telephone is engaged in the present call.
In an alternative embodiment according to the invention, a method of handling an incoming call includes a step of issuing a first signal to a target telephone to inform the target telephone of the incoming call. The method also includes a step of issuing a ringing signal to an incoming telephone to cause a speaker of the incoming telephone to provide a ringing sound to an incoming caller. The method further includes a step of waiting for a switch-hook signal from the target telephone, the switch-hook signal indicating a desire of a user of the target telephone to place a party to the present call into a hold status and connect to the incoming call. Finally, the method also includes a step of issuing a busy signal to the incoming telephone in order to cause the speaker to provide a busy sound if the switch-hook signal is not received by the time a variable reaches a predetermined limit.